Vasopressin

Solution for IV infusion: Patient with no fluid restriction: Dilute 50 units with 500 mL of NaCl 0.9% or dextrose 5% in water solution to make a final concentration of 0.1 units/mL. Patient with fluid restriction: Dilute 100 units with 100 mL NaCl 0.9% or dextrose 5% in water solution.

Hypersensitivity (including anaphylaxis). Chronic nephritis with nitrogen retention.

Patient with epilepsy, migraines or history of migraines; asthma, heart failure, vascular disease (particularly disease of the coronary arteries). Renal impairment. Pregnancy and lactation.

Significant: Water intoxication, decrease in cardiac index, reversible diabetes insipidus; extravasation leading to severe vasoconstriction and localised tissue necrosis; gangrene of extremities, tongue; ischaemic colitis.
Cardiac disorders: Chest pain, cardiac arrest.
Gastrointestinal disorders: Nausea, vomiting, diarrhoea, abdominal pain, flatulence.
Immune system disorders: Hypersensitivity, anaphylaxis.
Nervous system disorders: Headache, tremor, vertigo.
Renal and urinary disorders: Fluid retention.
Respiratory, thoracic and mediastinal disorders: Bronchospasm.
Skin and subcutaneous tissue disorders: Urticaria, hyperhidrosis.
Vascular disorders: Peripheral ischaemia, pallor, hypertension.

IM/IV/Parenteral/SC: C

This drug may cause vertigo, if affected, do not drive or operate machinery.

Monitor serum and urine sodium, urine-specific gravity, urine and serum osmolality, urine output, fluid input and output, ECG, blood pressure and heart rate during treatment. Monitor electrolytes, fluid status and urine output after discontinuation of treatment. Assess for signs and symptoms of digital or extremity infusion site for blanching or extravasation.

Symptoms: Water intoxication; ventricular tachyarrhythmias (including torsades de pointes), rhabdomyolysis; severe headache, confusion, listlessness, lethargy, drowsiness, weakness, pale skin, nausea, abdominal cramps or pain.

Management: Symptomatic and supportive treatment. Withdraw vasopressin. Give furosemide or small amounts of hypertonic saline for severe cases of water intoxication. Administer urea or mannitol infusions for cerebral oedema. Give amyl nitrite via inhalation or glyceryl trinitrate sublingually for anginal pain.

Increased antidiuretic effect with carbamazepine, chlorpropamide, clofibrate, fludrocortisone, urea or TCAs. Decreased antidiuretic effect with demeclocycline, norepinephrine, lithium and heparin. Increased effect on mean arterial blood pressure with ganglionic blocking agents. Additive effect on mean arterial blood pressure and other haemodynamic parameters with catecholamines. Prolonged effect on cardiac index and systemic vascular resistance with indomethacin. Increased pressor effect in addition to antidiuretic effect with drugs suspected of causing SIADH (e.g. SSRIs, haloperidol, chlorpropamide, enalapril, methyldopa, pentamidine, vincristine, cyclophosphamide, ifosfamide, felbamate).

Decreased antidiuretic effect with alcohol.

Description:
Overview: Vasopressin, an antidiuretic hormone, is a polypeptide hormone secreted by the neurons of the supraoptic and paraventricular nuclei of the hypothalamus and stored in the posterior pituitary (neurohypophysis) in mammals.
Mechanism of Action: Vasopressin stimulates V₁ receptors on vascular smooth muscle coupled to phospholipase C, causing the release of intracellular calcium, resulting in vasoconstriction. Additionally, vasopressin stimulates V₂ receptors which are coupled to adenyl cyclase, thereby stimulating antidiuresis.
Synonym(s): Argipressin, antidiuretic hormone (ADH).
Pharmacodynamics: In vasodilatory shock, vasopressin increases systemic vascular resistance and mean arterial blood pressure, and the pressor effect is proportional to the infusion rate of exogenous vasopressin. Vasopressin is also associated with the reduction of heart rate and cardiac output. Study shows no evidence of tachyphylaxis or tolerance to the pressor effect of vasopressin.
Onset: Antidiuretic: 1-2 hours. Vasopressor effect: Within 15 minutes (continuous IV infusion).
Duration: Antidiuretic: 2-8 hours (SC). Vasopressor effect: Within 20 minutes after termination of IV infusion.
Pharmacokinetics:
Distribution: Volume of distribution: 140 mL/kg.
Metabolism: Metabolised in the liver and kidneys into inactive metabolites.
Excretion: SC: Via urine (5% as unchanged drug). IV: Via urine (approx 6% as unchanged drug). Elimination half-life: 10-20 minutes.

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 9833460, Vasopressin, 1-(1-mercaptocyclohexaneacetic acid)-2-(O-methyl-L-tyrosine)-8-L-arginine-. https://pubchem.ncbi.nlm.nih.gov/compound/Manning-compound. Accessed Dec. 18, 2025.

Store between 2-8°C. Do not freeze. Protect from light.

Antidiuretics / Haemostatics

H01BA01 - vasopressin (argipressin) ; Belongs to the class of vasopressin and analogues. Used in posterior pituitary lobe hormone preparations.

Argipressin 20 international units/mL Solution for Injection (Mercury Pharmaceuticals Ltd). MHRA. https://products.mhra.gov.uk. Accessed 09/12/2025.

Argipressin [Vasopressin]. UpToDate Lexidrug, Lexi-Drugs Multinational Online. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 09/12/2025.

Brayfield A, Cadart C (eds). Vasopressin. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 09/12/2025.

Hanlim Vasopressin Injection 20 IU/mL (Imeks Pharma Sdn. Bhd.). National Pharmaceutical Regulatory Agency - Ministry of Health Malaysia. https://www.npra.gov.my. Accessed 09/12/2025.

Joint Formulary Committee. Vasopressin. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 09/12/2025.

Link Pharmaceuticals Ltd. Pitressin 20 Pressor Units Solution for Injection data sheet 28 March 2024. Medsafe. http://www.medsafe.govt.nz. Accessed 09/12/2025.

Vasopressin Injection, Solution (Fresenius Kabi USA, LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 09/12/2025.

Vasopressin. UpToDate Lexidrug, AHFS DI (Adult and Pediatric) Online. American Society of Health-System Pharmacists, Inc. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 09/12/2025.